![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
The finite arithmetic sequence is 1 + 4 + 7 + 10 + 13 + 16 + 19.
\(Apply sum of a finite arithmetic sequence formula: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=ca177c126c73bf9565cb54c9b1253a6a.png\")
)
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=f11d15b5f0f862180c9e2b26abff8489.png\")
(Substitute 7 for n, 1 for ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=985489fbb08561afbc72dc05ba153f35.png\")
and 19 for ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=cca91b1273c7261c65136429adeaf230.png\")
)
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=75f9856315abaf04a5cde3f8a7119921.png\")
(Simplify)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
The sum of the finite arithmetic sequence is 70.